Lazarus Pascal Requires Chilkat v11.7.0+

Add an Image (Logo) Watermark to a PDF

See more PDF Watermark Examples

Demonstrates an image watermark placed in a corner of every page. The image is a PNG or JPEG given either by path ("image.path") or, as here, as base64 in the JSON itself ("image.base64"), which suits a server that keeps its logo in a database rather than on disk. PNG transparency is kept. Giving only a width keeps the aspect ratio, and the units member says those numbers are inches rather than points. Lazarus Pascal

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Pdf,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  pdf: TPdf;
  json: TJsonObject;
  jsonOut: TJsonObject;

begin
  success := False;

  //  This example requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  //  The PDF used in this example is available at four_pages.pdf

  pdf := TPdf.Create;
  success := pdf.LoadFile('qa_data/pdf/four_pages.pdf');
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  json := TJsonObject.Create;
  json.UpdateString('type','image');

  //  A small PNG logo, base64 encoded.  Use "image.path" instead to name a PNG or JPEG file:
  //     ignore = json.UpdateString("image.path","logo.png");
  json.UpdateString('image.base64','iVBORw0KGgoAAAANSUhEUgAAAGAAAAAgCAYAAADtwH1UAAAApElEQVR42u3a7QmAIBgAYTdpo/ZphhZti6IBylLrlXoO/G3cIeFHSgAAFDKM08rCy8Jzg6Ug8UJ0JF+EDuSXRGgxX8+jufxlTk0nFuCCiF360aidXICMiDP5uQgCXAxQI782ggAHEu7IP4sgQOcBIMA35ItgBQhQEqBmtbX6xl//hAUI3gcIELwTFiD4LEiA4NNQAYLvA+BGzJ0wvIrwLggA8DgbwPbrr8c7+lkAAAAASUVORK5CYII=');

  //  The size to draw it at.  Give only the width and the height follows the aspect ratio.
  json.UpdateString('units','in');
  json.UpdateNumber('image.width','1.5');

  //  Bottom-right, half an inch in from the page edges.
  json.UpdateString('position.align','bottomRight');
  json.UpdateNumber('position.margin','0.5');
  json.UpdateNumber('opacity','0.85');
  json.UpdateString('id','logo');

  jsonOut := TJsonObject.Create;
  success := pdf.Watermark('add',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;
  WriteLn('id: ' + jsonOut.StringOf('id') + ' pages: ' + jsonOut.StringOf('pages'));

  success := pdf.WriteFile('qa_output/four_pages_logo.pdf');
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  //  Sample output:

  //  id: logo pages: 1-4


  pdf.Free;
  json.Free;
  jsonOut.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.